This proposal is designed to examine the continuity/discontinuity of alcohol consumption patterns and alcohol problems over the transition to marriage and is guided by a probabilistic-developmental framework (Zucker, 1993). From this perspective, changes in drinking risk over developmental transitions are influenced by both the preceding risk status as well as changes that arise as a function of the developmental transition in the individual, in his or her relationships, and in the social environment. Thus, observed reductions in drinking over the marital transition could arise from individual difference factors, relationship factors, or peer and social network factors. Methodologically, the project involves recruiting 600 couples, age 18 to 35, as they apply for their marriage license for their first marriage, and assessing these couples at the time they apply for their marriage license, at 12 months postmarriage, and at 24 months postmarriage. The assessment, which will be identical for husband and wife, will include measures of the following substantive domains: (1) Drinking Patterns and Problems; (2) Individual Difference Factors (i.e., Family History of Alcoholism, Socialization, Negative Affect); (3) Marital Quality; (4) Social Network Characteristics. Structural equation modeling will be utilized to examine both the cross-sectional and the longitudinal relationship of individual difference factors, marital and family factors, and social network factors to the alcohol use and problems of both husbands and wives. It is predicted that a model emphasizing the mediational role of social networks will best describe changes in drinking though individual risk factors and marital quality may also impact drinking. In addition, the study will assess whether the drinking trajectories over the two years are comparable for those going through the marital transition in a normative fashion versus those going through the transition by one of several nonnormative paths (late first marriage, presence of children prior to marriage, extensive cohabitation prior to marriage) and whether subsequent transitions to parenthood, or other major events and environmental stressors common to this developmental period, have a further impact on drinking and drinking problems.